Evaluation of Journal Bearings of Various Materials in Low-Viscosity Fluids, Liquid Nitrogen, and Liquid Oxygen.
Abstract
An experimental investigation was undertaken to determine the feasibility of operating journal bearings in cryogenic liquids at surface speeds comparable to those of current generation oxidant turbopumps. Tests were conducted with 1.0- and 1.5-inch-diameter bearings. Results from tests in liquid nitrogen and liquid oxygen were generally poor due to the difficulty of maintaining a hydrodynamic film. It is hypothesized that boiling of the cryogenic fluids may have occurred within the bearing clearance area, creating a two-phase-flow condition. A sharp decrease in the effective viscosity and in the bearing load-carrying capacity resulted. The best performance from tests with journal bearings fully immersed in liquid-oxygen was obtained with (1) fused polytetrafluoroethylene (PTFE) coated wrought-nickel-copper alloy sleeves, (2) a 15-percent glass-filled PTFE liner on steel, and (3) PTFE plus lead in sintered bronze. These materials were capable of sustaining moderate loads at surface speeds to 76 feet per second for a short duration. Liquid-oxygen pressure fed to the bearings at approximately 5 pounds per square inch gage above atmospheric pressure (boiling point,- 302 deg F) did not improve performance over the tests fully immersed at atmospheric pressure. jg p3
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- ADA306097
Entities
People
- Robert E. Cunningham
- William J. Anderson
Organizations
- National Aeronautics and Space Administration